The field of the present invention is injection control systems for internal combustion engines of a multicylinder design.
Fuel injection systems have been developed in recent years which are capable of controlling injection timing impulses responsive to a plurality of engine conditions and operating modes. Such systems generally employ electrical control units which measure such things as the location of the engine camshaft for timing, a pressure sensor for engine manifold pressure, a throttle position sensor and the like. Such systems detect the rotational sensor and pressure sensor inputs, convert the inputs to a control signal which actuates an injector actuator at the injector nozzle. In this way, timing and quantity of injection may be controlled.
Such systems have come to be employed for such advantageous uses as increased performance and increased fuel economy. With sufficient complexity, greater control can generally be achieved with an injection system than with carburetion. For improved mixture control, accurate sensing becomes of greater importance. However, injection systems are relatively expensive and general control units have been configured in single groups of components.
With multicylinder engines and especially such engines having multiple banks of cylinders, such unitary sensor groups have been located at representative locations for sensing engine conditions. A manifold pressure sensor may be located in one location within a common manifold or in one of two manifolds to provide input into the injector control unit. Such practice does not provide sufficient accuracy to obtain maximum benefit from such an injection system. Errors, signal incompatibility and inaccurate control can result from variations between banks of cylinders.